Volcano: what comes out by fishing
Loot · Volcano · Fish
4 loot lines. The right column is the only one that matters: how many of the game's 21 areas carry the very same line. The longer the bar, the less the trip is worth it.
The 4 lines
Resource Origin Present in Areas
Verdict: 1 lines out of 4 are only gathered here. The spread ranking says it on its own, and it will still be right the day a second area yields them.
The area's 6 activities
The rest of the area's loot, one click away. It is the natural way around this level of the tree: you do not go back up, you move from one activity to the next.